1. Technical Field of the Invention
The invention relates to a method for testing an object, in which a sectional image of the object is generated in at least a partial segment of the object by means of an X-ray computer tomographer. In the method, the object is clamped in a holding device, with which at least the partial segment is brought, in direction extending transversely to the segment, into a beam path between an X-rag source and an X-ray detector of the computer tomographer; then, the object and the holding device are pivoted, in at least one angular region, and relative to the X-ray source with the X-ray detector, about a first axis that extends through the partial segment and the beam path, with the partial segment remaining in the beam path. In specific angular increments, the X-ray detector generates a radiogram, and a cross-sectional image through the partial segment is reconstructed from these radiograms. The invention further relates to a device for executing the method.
2. Prior Art
A device of this type is known from EP 0 471 096 A1. The subject is a rim-mounted tire that is received at its end face in a holding device, which can travel on an adjusting sliding element on a pivoting device such that the pivoting axis of the pivoting device approximately axially passes through a tire cross section.
The beam fan of the X-ray device passes through the tire perpendicular to the pivoting axis; a holding arm of the beam receiver is positioned close to the tire and, depending on the pivoting position, is located in the open space of the rim or extends through it. The X-ray device is held on a sliding element that can be displaced perpendicular to the beam path and perpendicular to the pivoting axis of the tire, so a plurality of individual images of the one tire cross section can be generated corresponding to the different pivoting positions and the different displacement positions, and used in a cross-sectional representation. Further cross sections of the tire can only be obtained after the tire has been unclamped and fixed in a different angular position.
A computer tomographer that is particularly provided for testing cross sections of rim-mounted tires is known from EP 0 652 433 A. The tire is held in a holder about a pivoting axis perpendicular to the beam fan of an X-ray device. The tire can be displaced, in a sliding element, perpendicular to the pivoting axis and parallel to the tire plane, so the pivoting axis can be shifted into the one or the other of the two tire cross sections through which the beam fan passes, corresponding to the displacement positions. It is not possible to execute and allaround testing of the tire.
Numerous receptacles, such as sheet-metal boxes or the like, have some sort of folded-seam connections. For example, the lids or bottoms of tin cans are often connected to the jacket part through a folded-seam connection. Different forms of folded-seam connections are selected depending on the material and stress of the package. For sealing purposes, a sealing element may also be incorporated into a folded-seam connection.
The quality of a folded-seam connection depends on, among other things, the correct position of the material layers in the fold. At the present time, the quality can only be tested in a seal test (pressure test), mechanical stress tests or an external geometrical check of the dimensions. Cutting open the fold and removing and examining segments from the fold at defined or critical locations is the only way to obtain information about the correct material connection inside the fold. This is a destructive test, so, of course, only sample testing can be performed on packages in this method. Furthermore, the mechanical cutting open of the folded-seam connection can mechanically influence the sectional surface to be examined such that the original state of the folded-seam connection is no longer apparent. The test result is therefore skewed.
Because numerous boundary layers are present in a folded-seam connection, it is not possible to employ ultrasound methods or the like in testing.